Torque sensor
AssigneeKayaba Industry Co., Ltd.
InventorHideo Maehara
Life of this patent
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Abstract
A torque sensor detects a torque acting on a torsion bar provided between a first shaft and a second shaft on the basis of a magnetic flux density led to a rotating magnetic circuit portion from a magnetism generating portion. The magnetism generating portion includes a back yoke and a ring magnet. The back yoke includes a fitting portion fitted onto the first shaft, a joint portion to which the ring magnet is joined, and a stress reduction cutout that suppresses a transmission of a deformation stress generated in a radial direction of the fitting portion to the joint portion.
Claims4
A torque sensor that comprises a torsion bar that transmits a torque between a first shaft and a second shaft disposed coaxially, a magnetism generating portion fixed to the first shaft, and a rotating magnetic circuit portion fixed to the second shaft and detects a torque acting on the torsion bar based on a magnetic flux density led to the rotating magnetic circuit portion from the magnetism generating portion;
- the magnetism generating portion comprising:
- a back yoke that is fitted onto the first shaft;
- and
- a ring magnet that is joined to an end surface of the back yoke;
- and
- the back yoke comprising:
- a fitting portion that is fitted onto the first shaft;
- a projecting portion that projects from an end portion of the fitting portion in an axial direction of the first shaft;
- a joint portion to which the ring magnet is joined and that is formed on the projecting portion in a position offset from the fitting portion in the axial direction of the first shaft;
- and
- a stress reduction cutout that is a gap defined between the projecting portion and the first shaft and that is configured to suppress a transmission of a deformation stress generated in a radial direction of the fitting portion to the joint portion.
Dependencies are inferred from the claim text.